<em>Abstract.</em>—Using a combination of data sources and historic or contemporary accounts, we describe and document changes in the Hudson River watershed’s population size, agricultural and forested land uses, and the construction of dams, largely since the time of European colonization. Population within the watershed has grown from 230,000 at the time of the first census in 1790 to around 5 million today (not including parts of those boroughs of New York City outside the watershed, such as Queens). The watershed was almost entirely forested in 1609, with minor amounts of Indian agriculture. By 1880, approximately 68% of the watershed was farmland, but as soil productivity declined and industry created other jobs, much cleared land gradually reverted to secondary forest. Most land not in agriculture was forested and exploited first for lumber and tanbark and, later on, pulpwood for paper. The tanning industry existed from the 1700s, but reached its height in the mid-1800s, collapsing from a combination of resource (hemlock) exhaustion and market forces. Finally, available records list nearly 800 dams, ranging from 0.6 m to 213 m (Ashokan Reservoir) in height and with maximum storage of 1.07 km<sup>3</sup> (Sacandaga Reservoir), that were constructed from the early 18<sup>th</sup> century until 1993. The environmental legacies of these changes include effects on hydrology, soils, vegetation, biogeochemical cycling, sediment loading, and ecological relationships
Modeling Streamflow and Sediment Loads with a Photogrammetrically Derived UAS Digital Terrain Model: Empirical Evaluation from a Fluvial Aggregate Excavation Operation
